Patent GB-189919356-A (GB)
Title: Improvements in Type-writing Machines.
Filed: 1899-09-26
Granted: 1899-12-23
Abstract: 19,356. Clark, A. M., [Wagner Typewriter Co.]. Sept. 26. Type-writers.-Relates to type-writing machines, and comprises improvements in the platen-shifting mechanism, inking-ribbon feeding and guiding devices, detachable envelope guide, and keyboardlocking arrangements, and in the feed-roller system which co-operates with the platen. Figs. 5 and 6 are vertical sections taken towards the left and right hand sides of the machines respectively, looking outwards in each instance. The carriage 102 is supported in part by a roller 104, Fig. 5, which travels on a rod 103. The platen 3 is supported in the platen casing 2<a>, which is carried by pivoted links 4. A roller 6 carried by the platen casing rests on a rail 7, and the shifting of the platen to print upper-case characters is effected by the vertical movement of this rail. A pair of shafts 79, 64 carry two series of rollers normally spring-pressed against the platen through openings in a guide-plate forming the lower portion of the platen casing, and a pair of cam-actuated arms is provided which enables the shafts to be lowered so as to withdraw the rollers from the platen to release the paper when required. The rail 7 is carried by a pair of bell-crank levers 8, 8<a>, secured on a common rock-shaft 10, and an adjustablymounted spring 25 serves to partially balance the pressure of the platen and its casing upon the rail 7. The shifting of the platen is effected by depressing a key lever, Fig. 6, which is pivoted at 21 and is controlled by the spring 22. The vertical arm 23 of this lever actuates the bellcrank lever 8 so as to raise the platen. During the depression of the lever the pin 26 presses forward the pawl 27 and turns the rod 28, at the further end of which is secured the lever 30, Fig. 5. The forward end 18 of the lever 14 (pivoted at 15) is thus depressed, and the rear end rises so that the lug 11 on the lower end of the lever 8<a> passes from the locking-recess 12 to the recess 13. When, however, the pin 26 reaches its lowest point, the pawl 27 slips over it so as to lock the key lever, and the lever 30 at the same time turns so as to release the lever 14, the rear end of which falls so as to bring the lug 11 into the locking- recess 36. The machine will then print uppercase characters until by the depression of the key lever 32 the lever 30 is turned so as to release the shift-key lever 19, and at the same time lift the rear end of the lever 14 so as to allow the lug 11 to return to the locking-recess 12. When it is desired to print one upper-case character only, it is sufficient to depress the key lever 32, the vertical arm 23 of which actuates the lever 8<a>, while the lever 14 is raised to lock the lug 11 in the recess 13. The locking of the lug 11 in the various positions is designed to prevent vibration of the platen. The inking-ribbon 86 passes between a pair of spools 81 mounted on shafts 41 actuated by bevel gearing from ratchet-wheels 37, 38. Each ratchet-wheel is provided with a reciprocating pawl 42, the effective throw of which is controlled by an adjustable angular plate 59, and with a stop pawl 43. Either pair of pawls can be thrown into action by means of a controlling-lever, the opposite pair being simultaneously released ; the movement of the ribbon can thus be reversed when required. The pawl 42 is reciprocated by connection of the shaft 44 with the spacing- mechanism, which is operated by a universal bar placed in the path of the type-bars, or by a wrist bar at the front of the machine. The spools 81 are provided with casings 84 slotted so as to allow of the passage of the ribbon and serving as guides to prevent the ribbon dropping off the spool if slack. A detachable guide for envelopes, postcards, or narrow papers consists of a plate or finger 100, Fig. 3, carried in the centre of a spring-controlled and easily-detachable rod 90 secured parallel with the platen. The keyboard locking-arrangements are as follows :-A stud 107, Fig. 5, projecting from the carriage comes towards the end of its path into contact with a cam 108 adjustably secured to a rock shaft 111 extending along the front of the machine. The depression of the cam causes the movement of the arm 115, and the pin 119 acting on the inclined surface 120 turns the lever 122 so as to lift the bell hammer 123, which strikes the bell 124 as soon as the pin 119 has passed beyond the surface 120. Shortly afterwards the pin 116 reaches the stud 118 and turns the lever 117, which throws a universal bar into the path of catches on the key levers and thus locks the keyboard. By the depression of a button secured to this universal bar, it can be forced backward to allow one or two extra characters to be printed. An adjustable marginal stop is provided to limit the movement of the carriage towards the right.